Catalytic electron donor-acceptor complex triggered cascade radical trifluoromethylation/cyclization of N-isopentenyl aldehyde hydrazones

Abstract

Photocatalytic trifluoromethylation/cyclization of N-isopentenyl aldehyde hydrazones triggered by catalytic electron donor−acceptor (EDA) complex was developed for the construction of C5-trifluoromethylated tetrahydropyridazines. Catalytic amounts of tris(4-bromophenyl)amine was used as electron-donor and trifluoromethyl thianthrenium triflate as the acceptor to generate trifluoromethyl radical after irradiation. This environmentally benign methodology eliminates the need of photocatalyst, offering a straightforward and efficient approach to access C5-trifluoromethylated tetrahydropyridazines.